Fungi, Ascomycetes, Ustilaginales, Uredinales . Fig. 10:. Polystigma rtibrumTiQ,.; maturearchicarp, x Koo; after Blackmail Fig. 103. Xylaria polymorfha (Pers.) embedded in stroma, x 1000. readily be derived from the first. It occurs in forms where the perithecium isimmersed either in the substratum or in a stroma, and its essential characteris the prolongation of the tip of the archicarp to form a trichogyne-like01 an. The appearance of this structure is associated with the developmentofspermatia in spermogonia. Archicarps of the type in question are foundin Polyst
Fungi, Ascomycetes, Ustilaginales, Uredinales . Fig. 10:. Polystigma rtibrumTiQ,.; maturearchicarp, x Koo; after Blackmail Fig. 103. Xylaria polymorfha (Pers.) embedded in stroma, x 1000. readily be derived from the first. It occurs in forms where the perithecium isimmersed either in the substratum or in a stroma, and its essential characteris the prolongation of the tip of the archicarp to form a trichogyne-like01 an. The appearance of this structure is associated with the developmentofspermatia in spermogonia. Archicarps of the type in question are foundin Polystigma among the Hypocreales and in Gnomonia, Poronia andMycosphaerella among the Sphaeriales. In all these genera, however, thetrichogyne appears to be merely vestigial; in Polystigma it never reachesthe exterior of the host-leaf, in Gnomonia its connection with the coiledoogonial region is doubtful and in Mycosphaerella and Poronia it degeneratesearly. In Polystigma the ascogenous hyphae arise from vegetative cells andnot from the archicarp and it is at least possible that the same is the casein the other genera named. A compariso
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectfungi, bookyear1922
